In 1817, Gallium CLAEYSSENS' son transforms the oil mill into a jenever distillery, bringing much more profit at that time.

There were numerous advantages of creating a distillery at Wambrechies:

• the presence of the Deal Canal, having been used since ever by boats that brought cereals to produce jenever (and later, they brought also coal);
   
• the presence of a water mill on the lock site since the 13th century to grind the grains into flour;
   
• the presence of ground water 30 meters deep, very pure, largely available, and cheap, necessary to produce the Claeyssens jenever;
   
• the presence of cattle breeders in the surrounding villages, who could use the swill (solid remainders after distillation).
   

From 1817 until about 1850, the Claeyssens distillery settles round the water mill and the offices next to the housekeeper's house, which existed already in the 18th century, and is still occupied by the present housekeeper.

The arrival of the steam machine about 1850 drastically changed the organisation of the distillery site. The Claeyssens family bought the surrounding land to extend the distillery and to build castles and villas, still to be seen while cruising on the Deûle. Steam enabled the installation of mills in the present building and supplied the necessary energy. The distillery, which produced jenever at 49% of alcohol vol. stretched as far as the Wambrechies Main Square, and had its own malt mill.

Jenever became the favourite beverage of the miners and the textile workmen, who were very numerous in the Nord-Pas de Calais region. It was used in coffee (la bistouille) or straight, and it was the indispensable 'tap on the shoulder' before descending into the mine.

About 1930, production reached its historic peak.

In 1935, the Claeyssens jenever was awarded at the International Exhibition in Brussels.

Due to the decline of the mining industry, and later if the textile industry, the consumers are less numerous and older. Most of the other distilleries in the Nord-Pas de Calais close their doors.

At the end of the 20th century, only three of them are left in the region, among which the one at Wambrechies. The Claeyssens distillery diversifies its production by creating high-class products and Old Malt, having aged in oak casks.